3 med. onions, finely chopped
1/4 c. butter, melted
2 lbs. ground beef
15 1/2 oz. jar plain spaghetti sauce
16 oz. can stewed tomatoes
3 c. sour cream
1 c. shredded Mozzarella cheese
4 oz. can mushrooms, stems and pieces (optional)
1 med. size box linguine
8 oz. Provolone cheese
1/4 c. grated Parmesan cheese
Garlic salt to taste

Saute onion in butter in large skillet until tender. Add ground beef, cook until brown, stirring to crumble beef. Add spaghetti sauce, tomatoes, mushrooms and garlic salt to meat mixture. Stir well and simmer 20 minutes. Meanwhile, cook linguine according to package directions and drain. Place half of linguine in deep 4 quart, greased casserole. Layer with half of meat sauce, half of Provolone, and half of sour cream. Repeat layers and top with Mozzarella and Parmesan. Cover and bake at 350 degrees for 30 minutes. Uncover and bake 15 minutes longer. Yield: 10-12 servings.